| 摘要 |
A method to improve the displacement efficiency of hydrocarbonaceous fluids from a formation where at least two horizontal perforated wellbores are utilized. One horizontal wellbore is placed at a lower level and another is placed at a higher level in said formation. Thereafter, a first displacement liquid immiscible with and having a density greater than hydrocarbonaceous fluids in said formation is injected into said lower horizontal wellbore. Afterwards, a second hydrocarbon immiscible displacement liquid having a density greater than said first liquid is injected into said lower wellbore. The second liquid displaces said first displacement liquid and hydrocarbonaceous fluids to said higher level in the formation. Subsequently, the displacing liquids and hydrocarbonaceous fluids are produced to the surface.
|
